A Mop is a tool commonly used for house cleaning, and a mop holder is a device for fixing the mop cloth. A conventional mop holder usually comprises a frame, a limb and a screw. The limb is jointed with the screw and is placed in an inner area of the frame, forming a space between the limb and frame. A shaft and a nut are further mounted on the frame. When changing a mop cloth, said nut which corresponds and joints with said screw is rotated, forcing the screw to move up/downwardly and causing reaction of the limb to release and hold the mop cloth. By size of the nut, a user usually can rotate by using thumb and index finger, causing difficulty when clamping the mop cloth. This technique also generates pain and discomfort.